• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.471-474
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• 2006

BIPV(Building Integrated PV) system can expect dual effects that reduce expenses for establishment of PV system by adding new function as outer covering material of building expect producing the electricity. But, there are many generation differences according to the exterior environmental facts(solar cell away, design and installation condition of interactive inverter system) Therefore, it is difficult to optimum design. Consequently in advance design system, we experiment 3kW BIPV(Building Integrated PV) generation. We concrete PV system efficient application of variable. BIPV system that is proposed in this paper, was established in Solar Energy research center of Chosun University, composed with system. This research is a basic study for application of building integrated photovoltaic system for builing.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.4
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• pp.589-595
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• 2008

Detent force of a permanent magnet linear motor(PMLSM) consist of cogging and drag forces, and should be minimized for high precision control purpose applications. This paper shows that the cogging force can be reduced effectively by employing 9 pole 10 slot structure. The drag force is minimized by optimizing the total length and shape of the exterior teeth of armature core simultaneously by using($1+{\lambda}$) evolution strategy coupled with response surface method. After optimization, the optimized PMLSM is proven to reduce 95% and 92.6% of the cogging and total detent forces, respectively, and give 12% and 6.4% higher Back-emf and thrust force, respectively, compared with a conventional 12 pole 9 slot structure under the same condition. Additionally, Simulation results by the proposed optimum design are verified by the experiment results.

• Special Issue of the Society of Naval Architects of Korea
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• 2015.09a
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• pp.41-45
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• 2015

In this study reviewed the validity of the estimated optimum trim by the numerical analysis. For this purpose, the numerical analysis of the trim optimization for 6500TEU container carrier and capesize bulk carrier were carried out using Star-CCM+, which results were compared with the results of model tests. The reliability of results of the numerical analysis was confirmed via comparing the resistance determined by the numerical analysis and model test. The performance of self-propulsion at each trim conditions were estimated using the calculated resistance by numerical analysis. The BHP at each trim condition were calculated by estimated performance of self-propulsion, which trend of results were confirmed similar trend of result of model test.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.1
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• pp.11-17
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• 2013

The use of wasted concrete can settle the environmental pollution and shortage of natural aggregate. However, recycled aggregate includes substantial amount of cement paste, so that these aggregates are more porous, and less resistant to mechanical actions than natural aggregates. Recently, the new manufacturing processes of high quality recycled aggregates were suggested such as heating. In this paper, for the purpose of manufacture of high quality recycled aggregates, the heating processes was considered to the existing process of recycled aggregates. To find the optimum process, the experiment was performed through the statistical design of experiment. The heating temperatures of 4 levels (300, 450, 600 and $750^{\circ}C$) and heating duration time (5, 20, 40, 60minute) were main experimental variables. Through the test results, it was found that the optimum manufacturing condition of coarse recycled aggregate was evaluated to be $600^{\circ}C$ and 40minute.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2006.03a
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• pp.217-236
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• 2006

In this study, the LCM was applied as the preliminary study for the cutterhead design of TBM and the drilling performance evaluation. The optimum cutting condition is obtained from the LCM tests and the effects of the design factors of IBM cutterhead, such as penetration depth and cutter spacing, on drilling performance are estimated. In this study, hence, to predict the accurate performance of TBM, instead of one-dimensional penetration depth applied in existing studies, three-dimensional cutting volume was quantified and measured. For this, the digital photogrammetry technique was applied to the LCM tests. Also, AUTODYN 2D was applied to investigate the applicability of the numerical analysis technique to simulate the cutting process of rock by the TBM disc cutter.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.11
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• pp.1652-1662
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• 2014

The present study investigated the optimum blending condition of protected fat, choline and yeast culture for lowering of rumen temperature. The Box Benken experimental design, a fractional factorial arrangement, and response surface methodology were employed. The optimum blending condition was determined using the rumen simulated in vitro fermentation. An additive formulated on the optimum condition contained 50% of protected fat, 25% of yeast culture, 5% of choline, 7% of organic zinc, 6.5% of cinnamon, and 6.5% of stevioside. The feed additive was supplemented at a rate of 0.1% of diet (orchard grass:concentrate, 3:7) and compared with a control which had no additive. The treatment resulted in lower volatile fatty acid (VFA) concentration and biogas than the control. To investigate the effect of the optimized additive and feed energy levels on rumen and rectal temperatures, four rumen cannulated Hanwoo (Korean native beef breed) steers were in a $4{\times}4$ Latin square design. Energy levels were varied to low and high by altering the ratio of forage to concentrate in diet: low energy (6:4) and high energy (4:6). The additive was added at a rate of 0.1% of the diet. The following parameters were measured; feed intake, rumen and rectal temperatures, ruminal pH and VFA concentration. This study was conducted in an environmentally controlled house with temperature set at $30^{\circ}C$ and relative humidity levels of 70%. Steers were housed individually in raised crates to facilitate collection of urine and feces. The adaptation period was for 14 days, 2 days for sampling and 7 days for resting the animals. The additive significantly reduced both rumen (p<0.01) and rectal temperatures (p<0.001) without depressed feed intake. There were interactions (p<0.01) between energy level and additive on ruminal temperature. Neither additive nor energy level had an effect on total VFA concentration. The additive however, significantly increased (p<0.01) propionate and subsequently had lower acetate:propionate (A/P) ratios than non-additive supplementation. High concentrate diets had significantly lower pH. Interactions between energy and additive were observed (p<0.01) in ammonia nitrogen production. Supplementation of diets with the additive resulted in lower rumen and rectal temperatures, hence the additive showed promise in alleviating undesirable effects of heat stress in cattle.

• Journal of the Korean Magnetics Society
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• v.12 no.6
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• pp.224-230
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• 2002

The statistical experiment method is employed to optimize the deposition condition of Co film with DC magnetron sputtering process. The statistical treatment results showed the significance value below 0.05, low RMS error and R-sq value close to 1, which implied that our experiment and design were very reliable. We found that the sheet resistance decreased to -1.83Ω/$\square$ with the deposition temperature, increased to 11.17Ω/$\square$ with the deposition pressure, and decreased into -0.65Ω/$\square$ with the DC power. We also confirmed that the sheet resistance uniformity was mainly influenced by the deposition temperature as it decreased -4.04％ at the temperature range of 25$\^{C}$∼147$\^{C}$. Finally, we report that the optimum condition of Co film using our statistical method of design of experiment is the deposition temperature of 25$\^{C}$, the deposition pressure of 12mTorr, and the DC power of 1500W.

• Korean Chemical Engineering Research
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• v.46 no.3
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• pp.610-618
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• 2008

It is not easy to compare the treatment processes and find an optimum operating condition by the experiments due to influent conditions, treatment processes, various operational conditions and complex factors in real wastewater treatment system and also need a lot of time and costs. In this paper, the activated sludge models are applied to four principal biological wastewater treatment processes, $A_2O$(anaerobic/anoxic/oxic process), Bardenpho(4 steps), VIP(Virginia Initiative Plant) and UCT(University of Cape Town), and are used to compare their environmental and economic assessment for four key processes. In order to evaluate each processes, a new assessment index which can compare the efficiency of treatment performances in various processes is proposed, which considers both environmental and economic cost. It shows that the proposed index can be used to select the optimum processes among the candidate treatment processes as well as to find the optimum condition in each process. And it can find the change of economic and environmental index under the changes of influent flowrate and aerobic reaction size and predict the optimum index under various operation conditions.

• International Journal of Highway Engineering
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• v.11 no.2
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• pp.1-15
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• 2009

Surface of exposed aggregate concrete pavements is consists of exposed coarse aggregate by removing upper 2$\sim$3mm mortar of concrete slab. Exposed aggregate concrete pavements have advantages of maintaining low-noise and adequate skid-resistance level during the performance period. In order to provide the successful exposed concrete aggregate pavement, uniform distribution of the coarse aggregate on pavement surface through adequate the mix design and exposing method. The mix design in concrete pavement is generally designed on the basis of strength, but mix design of exposed aggregate pavement employed in this study includes the consideration of noise and skid resistance, as well as strength. Smaller of maximum coarse aggregate is known to be effective for reduce noise level. Optimum mix design and exposing method of fine-size exposed aggregate portland cement concrete pavement that can reducing the noise and maintain the adequate level of skid resistance are proposed in this study. To consider the variation of optimum exposing time due to the hardening speed of mortar by climatic condition, quantitative is also suggested measurement of hardening state.

• Journal of the Regional Association of Architectural Institute of Korea
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• v.20 no.6
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• pp.17-23
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• 2018

The purpose of this study is to suggest 100MPa class ultra high strength concrete mix design model applying neural network theory, in order to minimize an effort wasted by trials and errors method until now. Mix design model was applied to each of the 70 data using binary binder, ternary binder and quaternary binder. Then being repeatedly applied to back-propagation algorithm in neural network model, optimized connection weight was gained. The completed mix design model was proved, by analyzing and comparing to value predicted from mix design model and value measured from actual compressive strength test. According to the results of this study, more accurate value could be gained through the mix design model, if error rate decreases with the test condition and environment. Also if content of water and binder, slump flow, and air content of concrete apply to mix design model, more accurate and resonable mix design could be gained.